Originally Posted by cfoxcvg
Here is a photo
to show the foot. You can also see the angle of the boom. This is with 10-15 mph wind
and the boom is well over the Port side, when pulled to center line it hangs very low.
Here's my armchair analysis - I presume both photos were taken at the same time. I copied the photos into a photo editor so I could magnify them and look at a few features.
- I am not sure if this is15 knots of wind
in the photo - the reef ties are are completely limp and the trailing edge tell appears to be flying to leeward a bit.
- It appears you are also motoring which will play tricks with the apparent wind.
- The main halyard is made and there is probably not 6 inches at the top. IMO the luff length is OK as indicated by the tight bolt rope
- The foot is very tight and the leech is very tight. In the first photo it even looks like the leech is hooked to windward indicating that the leech is too tight. It does not appear your sail has a leech line or I would suggest relaxing it.
- Due to the two blondes in photo 2 (nice) it is hard to say if you have a boom vang
(it appears not) but your mid-boom sheeting is "way" too tight for the conditions - this tight sheeting also lowers the boom and tightens the leech. You should sheet out and move the traveler to windward to release leech tension.
The boom lifts due to pressure in the sail. Vang and sheeting hold it down and "shape" the sail for performance, traveler adjusts for power. If the boom is not lifting, the leech is closed and the sail is not filling the vang, mainsheet, and leech line could all be too tight.
A couple of photos, close hauled with wind in the sails would be useful. One looking straight up the leech one looking straight up the windward side showing the shape and another from the beam showing overall perspective.
Originally Posted by boden36
Have you checked the straightness of your mast? Regards, Richard.
This is a distinct possibility. Photo 1 shows an extra heavy duty back stay and it's hard to tell due to parallax but it appears there is a distinct bend above the spreaders.
I don't see the forestay or you flying a jib
. If it is a masthead rig the forestay may be too long as well.
boats adjust the backstay for conditions - bending the mast aft does exactly what your sail is doing - moves the draft
, creates overbend wrinkles or what some call inversion of the sail, this can be desirable in certain conditions. Do you have a hydraulically adjustable backstay and a fractional rig? If so get the backstay off almost completely for the "zero" wind conditions indicated in your photos.
You have dual mid-shrouds and uppers. The upper work against the backstay and the mids keep the middle of the mast straight. The base of the mast may also be adjustable. You want to know how much prebend you have with no backstay on.
You can do this simple check. Get all the backstay off and get a bucket of water
. Put the bucket at the base of the mast and drop the main halyard in it. The bucket dampens sway in the halyard. Sight up the halyard and look at the gap I don't know how much gap is appropriate for your boat but if it is significant you will want to tighten the uppers to move the top forward and then adjust the mids to get the mast straight.
Originally Posted by Prerequisite
There is also the possibility that your sail is fairly bagged out. The 'how old is it' question is rather subjective, so 'how much use has it had' is more appropriate. Has the sail been used past it's serviceable life?
When is the boom 95 degrees to the mast, when the sail is up or when the boom is just hanging from the topping lift
? Keep in mind that the boom angle on most boats is controlled by a vang. The vang controls (among other things) the leech tension, so boom angles are a little fluid when it comes to sail trim. Also, while your diagonal wrinkles appear to come from the oversized sail, on a properly cut sail it is not uncommon to see some diagonal wrinkles like yours (to a much lesser degree though) on the bottom half or third of the sail. These are called 'overbend' wrinkles and can actually indicate proper trim.
I agree that a cunningham will help (but it won't solve the problem)- I find the vang and cunningham to be the most underused and under-appreciated trim lines.
In photo 1 you can see a fairly consistent curvature in the sail. The draft
is aft. To move the draft forward you have to get tension off the leech and tension off the backstay.
I would loosen everything up, go out in some wind, lift
the boom with the topper, get the tells to fly and have another look. I also think this sail is blown out. I don't think the foot, luff and leach dimensions are wrong, however.
-halyard tight enough to too tight
- too tight for light conditions
- way oversheeted - sheet for shape
- traveler to windward for power - traveler for power
- no wind - lift the boom with the topper to get some shape - the boom is heavy and is closing the leech
- check the backstay - completely off for these conditions
- what is the status of the forestay?
- sail likely blown out but do all the adjustments, get some wind in the sails (tells flying) and take more photos before recutting the sail.
In fact cutting the foot likely won't fix what is wrong. Imagine the distance from the goosneck to the masthead, the distance from the masthead to the boom end and the distance from the boom end to the goosneck. It's a triangle and from my seat teh perimeter of the triangle is tight (luff, leech and foot)